An industrial robot used in welding, for example, typically operates in synchronization with peripheral devices, such as a welding power supply, a positioner, and a slider. As the method for synchronization, a method in which communication control is performed over a network using, for example, RS-232C, RS-485, RS-422, Ethernet (registered trademark), or CAN (Controller Area Network) (registered trademark) is used.
As an example of the related art for synchronization between devices, PTL 1 describes a communication control device for communicating with one or more control devices over a network, including a non-periodic transmission unit that generates a transmission request at a given time, a periodic transmission unit that generates a transmission request at regular intervals, a communication unit that communicates transmission data of the non-periodic transmission unit and transmission data of the periodic transmission unit to the network, and a scheduling unit that transmits transmission content from the periodic transmission unit to the communication unit, computes a communication processing time taken to perform a communication process by the non-periodic transmission unit having a transmission request, obtains a remaining time in the regular interval of the periodic transmission unit, compares the communication processing time with the remaining time, and transmits transmission content from the non-periodic transmission unit to the communication unit.